var shopplist = [
	"catfish",
	"water",
	"tulips",
	"blue paint",
]

print("\(shopplist[0])") //catfish

shopplist[0] = "dog food"

print("\(shopplist[0])") //dog food

//草帽海盗团成员
var crews_ = [
	"路飞":"船长",
	"索罗":"副船长",
	"山治":"厨师",
	"娜美":"航海家",
	"神射手":"乌索普",
	"医生":"乔巴",
	"罗宾":"考古学家",
	"弗兰奇":"船匠",
	"布鲁克":"音乐家",
	"第十人":"X",
	
]

crews_["第十人"] = "甚平"

var ten_name_1:String? = crews_["第十人"] //结果：Optional("甚平")
print("草帽海贼团 第十人 猜测：\(ten_name_1)")

var ten_name_2:String! = crews_["第十人"]  //结果：甚平
print("草帽海贼团 第十人 猜测：\(ten_name_2)")


//定义一个空数组
let emptyArray = [String]()

//定义一个空字典
var emptyDictionary = [String:Float]()

emptyDictionary["张三"] = 23

var key = "张三"

print("\(emptyDictionary[key])")





